The suit accuses the Obama administration of failing to protect endangered birds and whales in approving the Cape Wind project, a set of 130 wind turbine generators to be installed on Nantucket Sound. The suit would mark the first legal challenge to the project since it was approved April 28 by Obama administration officials, who lauded it as a model of renewable energy production.

The plaintiffs, including Public Employees for Environmental Responsibility, the Alliance to Protect Nantucket Sound, Californians for Renewable Energy, Inc. and the Texas group Lower Laguna Madre Foundation, argue that the Interior Department failed to adequately assess the wind turbine project for its potential harm to birds and whales migrating off the Massachusetts coast.

Jessica Almy, an attorney for the plaintiffs, said that the Interior Department ignored recommendations from experts to require that wind turbines shut down during the heaviest periods of bird migration.

She alleged the Fish and Wildlife Service recommendation was removed from the proposal after the Interior Department received an objection from the project applicant, Cape Wind Associates.

Cape Wind Associates, owned by a private Boston-based energy company, wrote Interior in 2008 that the shutdown requirement was "not reasonable." The letter was sent to Interior's Minerals Management Service, currently under criticism for allegedly mishandling its oversight of offshore oil and gas drilling.The shutdown requirement would have included hours when power generated from the project was most important and would harm the project's financial viability, the company wrote.

Mark Rodgers, communications director for Cape Wind, said, "The impact on birds will be minor and the threats we're imposing on birds from burning fossil fuels and from climate change are far more severe and need to be mitigated."

The plaintiffs also argue that the project could harm right whales, citing reports that nearly 100 whales were recently observed feeding near the proposed project site.

Rodgers said that the of all the water bodies around Cape Cod, "the one with the least amount of whale traffic is Nantucket Sound."